Core

Small engine for handling step stages and sequences.

Supports:

• step stage (A + B)
• stage sequences (A+B → C)
• scoped actions (same stages in different contexts)
• sequence timeouts

Install

npm install @hotora/core

Basic usage

const controller = new SequenceController<string>();

controller.register(["Ctrl", "S"], {
  handler: () => console.log("Save"),
});

controller.addStep("Ctrl");
controller.addStep("S");
const fired = controller.process();
for (const [event, handler] of fired) {
  handler(event);
}

Keyboard example

const controller = new SequenceController<string>();
controller.register(["Ctrl", "S"], {
  handler: () => console.log("Save"),
});

window.addEventListener("keydown", (e) => {
  controller.addStep(e.code);
  const fired = controller.process();

  for (const [event, handler] of fired) {
    handler(event);
  }
});

window.addEventListener("keyup", (e) => {
  controller.removeStep(e.code);
});

Stages

controller.register(["Ctrl", "S"], {
  handler: () => console.log("Save"),
});

Sequences

controller.register(
  [
    ["Ctrl", "K"],
    ["Ctrl", "C"],
  ],
  {
    handler: () => console.log("Comment"),
  },
);

Execution order:

Ctrl+K → Ctrl+C

Scope

Scopes isolate actions so the same combos can exist in different contexts.

controller.register(["Enter"], { handler: submitForm }, "modal");
controller.addStep("Enter");
const fired = controller.process("modal");

for (const [event, handler] of fired) {
  handler(event);
}

Default scope:

$global

Sequence timeout

Default: 3 seconds

controller.register([["A"], ["B"]], {
  clearDuration: 5,
  handler: () => console.log("Triggered"),
});

API

register(sequence, setup, scope?)

Registers an action.

register(
  Combo | Sequence,
  {
    handler: (event) => void
    clearDuration?: number
  },
  scope?: string
): ActionId

addStep(step)

Add step to active steps.

Used for events like keydown.

process(scope?)

Processes a step.

Returns actions to execute.

const fired = controller.process();

for (const [event, handler] of fired) {
  handler(event);
}

removeStep(step)

Removes step from active steps.

Used for events like keyup.

unregister(id)

Removes registered action.

Event

Handler receives:

{
  sequence: Sequence;
  activeSteps: Set;
  timestamp: number;
}

License

MIT